As many of you know, Player Piano Co. has been producing a vacuum pump
kit for player pianos for many years. In the early years of production,
PPCo used American-made parts. However, back around 1997, RCA stopped
making the diac and triac used in the controller. Subsequently, the
parts came from Taiwan, Hong Kong and Mexico, and the failure rate increased
dramatically.

For those who have systems that were made after 1997 that have stopped
working, I have finally located the schematic for the controller.
I've sent the schematic to MMD and hopefully it will be put into the Technical
Section at the MMD web site. Suitable replacement parts are available
from Radio Shack.